On Fri 20-11-15 17:16:06, Dmitry Vyukov wrote: > Hello, > > On commit 8005c49d9aea74d382f474ce11afbbc7d7130bec (Nov 15). > > The program is: > > // autogenerated by syzkaller (http://github.com/google/syzkaller) > #define _GNU_SOURCE > #include <unistd.h> > #include <sys/syscall.h> > #include <sys/eventfd.h> > #include <sys/sendfile.h> > #include <fcntl.h> > > #define SYS_memfd_create 319 > > int main() > { > int r1 = eventfd(0, 0); > int r2 = syscall(SYS_memfd_create, "", 0); > unsigned long n = 1<<30; > fallocate(r2, 0, 0, n); > sendfile(r1, r2, 0, n); > return 0; > } > > It can be executed under non-privileged user and creates an unkillable > process. It probably will terminate eventually, but it can take > days/weeks. Note that "mm: make sendfile(2) killable" > 296291cdd1629c308114504b850dc343eabc2782 is merged, so it is something > different. Though, probably similar. Thanks for the report. Yes, the nature of the problem is similar but here we don't hit standard filesystem write path where a signal test is. I'll send a fix which fixes the issue for me shortly. BTW, this test actually doesn't hang for me but rather burns CPU all the time and thus causes also softlockups / RCU stalls. I'll send a fix for that as well. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
